Preparation Of HMPC Reinforced Acrylic-Based Elastomer And Its Structural Color Material

Photonic crystal materials are widely used in the fields of sensing,anti-counterfeiting,color rendering,and packaging.However,photonic crystal composites still have problems such as weak mechanical strength,poor flexibility,and poor self-recovery performance.For optical sensors that respond to electricity/magnetism,temperature,etc.,structural color changes due to deformation will interfere with their optical readings.In response to the above problems,this thesis prepared a coordinated elastomer that combines strain and strength with excellent self-recovery performance through molecular design.The coordination elastomer is effectively combined with PS@SiO₂ photonic crystal material to prepare a photonic crystal-elastomer composite material,which not only has excellent mechanical properties but also has mechanical non-discoloring properties.The specific work is as follows.An elastomeric material?HA-HPMC-Zn?with high strength and excellent self-recovery was prepared by introducing a macromolecular chain hydroxypropylmethylcellulose?HPMC?into a double-crosslinked network of Zn²⁺complex Poly?acrylic acid-co-hydroxyethyl acrylate?.Acrylic acid and hydroxyethyl acrylate are radically copolymerized to form a covalent support network structure.By urea to control the occurrence of complexation reaction.The carboxyl group in the covalent network forms a coordination network structure with Zn²⁺in situ so that the originally loose network structure becomes compact;Besides,HPMC is interspersed in the network structure,which makes the mechanical properties of the elastomer material significantly improved,the fracture stress of the material reaches 10 MPa,and the strain reaches 560%.The introduction of coordination bonds has given the elastomer material excellent self-recovery characteristics.Under the condition of 20%tensile strain,the self-recovery rate reaches 93%;and after 100 cycles of stretching and compression,no fracture occurs and the self-recovery rate reached 88%and 90%,respectively.The coordination elastomer and PS@SiO₂ photonic crystal are effectively combined to make a photonic crystal-elastomer composite material?HA-HPMC-Zn PCs?.First,the PS@SiO₂ nanospheres were prepared into photonic crystal templates by vertical solvent evaporation.Then,the elastomer solution is filled into the gaps between the photonic crystals,and the polymerization and complexation reactions are performed respectively to achieve an effective combination of the elastomer and the photonic crystals.The prepared composite material can have both the mechanical properties of Zn²⁺coordination elastomer and the optical properties of photonic crystal,and its structural color does not change due to deformation and has stability.This is mainly because the coordination of Zn²⁺makes photonic crystal unable to release energy by changing lattice spacing and effective refractive index;on the micro-level,the stress is released by locally formed cracks;on the macro level,the structural color remains unchanged.Incorporation of hydroxypropyl methylcellulose improves the mechanical properties of the material,making its tensile strength and toughness up to 10 MPa and 11 MJm^-3,respectively.The introduction of coordination bonds also gives the material excellent self-recovery performance.The maximum stress before and after recovery is 2.5 MPa and 2.4 MPa when the strain is 40%.After 100 cycles of stretching,bending,and compression,the material did not break and the structural color remained unchanged.